Visualping - Visualping is the easiest to use website checker, webpage change monitoring, website change detector and website change alert software of the web. Read more about Visualping.
RSS.app - Monitor the web the way YOU want to.
WebSite-Watcher - WebSite-Watcher detects website updates and highlights all changes in the text. WebSite-Watcher monitors web pages, password protected pages, disucssion forums and much more.
FetchRSS - Generate RSS out of any website.
Update Scanner - Update Scanner is a Firefox extension to monitor web pages for updates.
FiveFilters Feed Creator - Create feed from elements (e.g. links) extracted from a given web page